Design, synthesis, and biological evaluation of hybrids from both nitrones with eNOS-mimicking activity and selective...

Ischemic stroke (IS) involves complex pathologies such as excitotoxicity, oxidative stress, and inflammation. Targeting inducible nitric oxide synthase (iNOS) which produces damaging levels of NO, while sparing neuroprotective endothelial NOS (eNOS) activity, represents a promising therapeutic strategy. We designed and synthesized a series of hybrids from both nitrones with eNOS-mimicking activity and iNOS inhibitors. Among them, compound 13h exhibited selectivity for iNOS (49.2- and 43.3-fold selectivity over nNOS and eNOS, respectively). And 13h demonstrated significant neuroprotective effects across multiple in vitro models, including oxygen-glucose deprivation/reoxygenation (OGD/R) and H₂O₂-induced damage in neuronal and endothelial cells. In a transient middle cerebral artery occlusion (tMCAO) rat model, 13h (30 mg/kg, i.v.) markedly reduced cerebral infarction volume (>80 %) and improved neurological function. Mechanistic studies suggest its efficacy stems from anti-oxidant, selective iNOS inhibition, and 3-nitrotyrosine (3-NT) suppression activities. Thus, 13h serves as a novel compound with a multi-target activity against IS.